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I (No Mqdel.) 2 Sheets-Sheet 2.

. G..LEVER.. EXGITING GIRGUIT FOR DYNAMO ELEGTRIG MACHINES.

No. 291.209. FIG 3 Patented Jan. 1,-1834'.

- v UNITED STATES -ATENT @riucie.

CHARLES LEVER, OF BOVDON, COUNTY OF CHESTER, ENGLAND.

EXCITING-CIRCUIT F OR DYNAMO-ELECTRIC iVIACHlNES.

SPECIFICATION forming part of Letters Patent No. 291,209, dated January 1, 1884.

Application filed February 19, 1883/ (No model.) Patented in England May 3, 1882, No. 2,092; in France November 3, i882,

and in Belgium November 4, 1892.

principle, and where thecarbon points are separated before the current is sent through the lamp, such currents are generated by what is called a self-exciting continuous-current dynamo machine-e. 9., a series dynamo. If, for example, anumber of such lamps are placed in series or single circuit, the carbon points on the lamps being separated, the only path for the electric current is through the shunt-cir cuits on the electro-magnets or solenoids in the lamps; but the resistance of these shunt-circuits would be so great that the said dynamomachine could not excite itself through this resistance. One method of obviating this difficulty is as follows: It is well known that when a dynamo-electric machineis excited the iron parts of the machine become strongly magnetized, and the magnetism of any of these parts-whichever part is most convenient-is, according to my invention, utilized to attract an armature. Figure 1 shows such an arrangement. D is a dynamo-machine, of which B B are the terminals, to which are connected, for example, four lamps, L, as shown. A is an armature capable of moving 011 a pivot or fulcrum at A. Z is the iron loop of the dynamo D. The figure shows the lamps in action. A resistance, R, about equal to the resistance of the four arcs L, is connected as follows, viz: from -I bindingscrew B to the armature A. A short thickwire connects metal stud S with the negative binding-screw B.

G is a spring-contact, shown in section at Fig. 2, where A is the armature, through which passes a large screw, F, having a hollow part for the reception of the end of spiral spring J, and forces the contact-piece O, which has a stem guided through screw 1?, onto the metal stud S, connected to the negative terminal B on the dynamo D. The screw F serves to ad just the tension of spring J. Before the lamps shunt-circuit and resistance R until the iron loop Z becomes sufficiently magnetized to attract armature A, thus causing the said shuntcircuit to be broken, whereupon all the cur rent will flow through the main circuit and lamps L, thus causing the shunt electro-mag nets or solenoids in the lamps to instantly form their arcs. so that the armature A will be attracted by the iron loop Z of the dynamo when said dynamo is excited to the minimum electric energy necessary for actuating the magnets of the lamps; hence the armature A will be held firmly to the loop Z bythe magnetism until such magnetism sinks below the minimum energy, when the spring H will move such armature and automatically close the circuit through the resistance R.

When it is not desirable or convenient to utilize the magnetism of the iron loop or other iron projection of the dynamo to allow the dynamo-machine to excite itself, as already de scribed, an electro-magnet orsolenoid, preferably wound with a resistance equal to that of the arcs L, is connected in the dynamo shuntcircuit, and an armature, A, capable of moving on'a pivot, A, fixed at one end of the armature A, is used. At the end of the armature A opposite to the pivot A is a metal piece, 0, sliding through the said armature, and a spring, J, presses this metal piece 0 upon a metal stud, S. (Shown in Figs. 3 and 4.) The electromagnet or solenoidEinthe shuntcircuit has the ends of its coilswhich are of coarse wire having, as already stated, a re: sistance about equal to that of the lamps L- connected one to the pivot Aof the armature A, and the other to one of the binding-screws of the dynamo-electric machine, or to the binding-screwsB B on the insulating-plate I, and thence to the dynamo, the said electro-magnet E, armature A, and metal stud S being The spring H should be adjusted fixed on the plate I of the insulating material such as wood or vulcanite the metal stud S being made flush therewith. When the metal piece 0, sliding through screw F on the armature A, is resting on the metal stud S, and the said metal stud. is connected by a wire of low resistance, as shown at Fig. 3, to the other binding-screw of the dynamomachine, the oz; citing shuntcircuit is complete, viz: from the positive binding -screw of the dynamo through the coils of the electro-magnet E or solenoid. to the pivot A of the armature A, through the armature and metal piece Oto the metal. stud S and to the negative binding-screw of the dynamo, or vice versa. "When the shuntcircuit is thus completed and the dynamo has excited itself, the armature A will be attracted by the said eleetro-magnet E or solenoid, the screw F having been so adjusted that the armature A will not be attracted until the dynamo has sufficiently excited itself and the metal piece 0 will leave its metal stud S, thus breaking the shunt-circuit and allowing the current generated by the dynamo to actuate the lamps L. as before. The latter device may be placed at or in the electric lamp itself by arranging an eleetromagnet or solenoid (in this case wound with a resistance rureferably equal to the are) in derivation to the are; but such arrangements would not he practicable with a number of lamps, on account of the (lit fieulty of causing all the devices to break the shunt-circuits at the same time. The said device may be fixed in any other convenient place and connected with the dynamo, so that the lamps can be started from any desired place. I do not limit myself to the devices above dcscribedas, for example, a simple switch or key may be used to form this exciting shunt-circuit, and tobreak the said shuntcircuit by hand when the dynamo has excited itself; but this arrangement, not being automatic, would necessitate some skill on the part of the operator in order to ascertain to a nicety when the dynamo had suflicicntly excited itself for him to break the shunt-circuit by releasing the key or moving the switch. The devices hereinbefore described are, however, when once adjusted, automatic.

Having now described the nature of this invention and the manner in which it is or may be carried intocffect, I claim-- 1. In combination with a series dynamoelectric machine and with shunt electric-arc lamps arranged in series, a shunt or derived circuit having a resistance equal to said lamps, and through which the current passes for the purpose of exciting the dynamo, and a circuit-breaker for breaking the said shuntcircuit when the dynamo has excited itself, and causing the current to pass through the magnets of the lamps to form their arcs, sub stantiall y as specified.

2. In combination with a series dynamo electric machine and with shunt electric-arc lamps arranged in series, the magnet E in a shunt-circuit from the dynamo D, and having a resistance about equal to the arcs, the pivotcd armature A, spring J, contact-piece O, stud S, and wire connections, substantially as specified, whereby the armature will be moved when the dynamo has excited itself, thus breaking said slnint-eircuit and causing the current to pass through the magnets of the lamps and to form their arcs, substantially as specified.

CHARLES LEVEP. \Vitnesses:

F. Baum-5r, Jenn Dmx. 

